Found on Not Always Right:

For You, We’re Always Closed
RESTAURANT | LANCASTER, PA, USA
(The diner I work in is a 24 hour restaurant, and closes only on Thanksgiving Day, Christmas Day, and New Years Eve after 6pm.)
Me: “Hello, thank you for calling [diner]. How may I help you?”
Caller: “Yes, what time do you close?”
Me: “We don’t close until Thanksgiving–we’re 24 hours.”
Caller: “I don’t care what time you close on Thanksgiving, I want to know when you close TONIGHT.”
Me: “… 5 pm.”
Caller: “THANK YOU.” hangs up

Thankfully the job I work in which I have to deal with customers most of them are cool.